When a liquid food is processed, situations occasionally arise where the product must be circulated across a balance tank. The process may be some type of heat treatment, such as pasteurization or UHT-treatment (Ultra High Temperature). Other processes may also occur. A situation which may occur is, for example, when the correct temperature has not been reached in the heat treatment equipment. The liquid food product may be some form of dairy produce, such as milk, cream or the like.
When a liquid food product is circulated over a balance vessel or tank, it is almost inevitable that air will be admixed into the product. Air in a dairy product which is to be heat treated markedly increases the risk of fouling, i.e. burning of the product onto surfaces in the heat treatment equipment. Air also affects the standardization of milk products in that a lower level of accuracy will be achieved. There will also be a reduction of accuracy in other measurement equipment. Air in a food product also has a harmful effect of the homogenization of, for example, milk.
One method of avoiding the admixture of air into the food product is that the inlet in the balance tank or vessel is positioned below the liquid surface of the tank. This is an efficient method of avoiding the admixture of air, but unfortunately suffers from the drawback that there is a slight risk that treated product will be mixed with untreated product. In some countries, there is moreover legislation in place which prevents the adoption of such a solution.